The field of the invention is electrical generation and the invention relates more particularly to wind-driven electrical generation.
Wind has been used to drive machinery for centuries, but recently with the concern of greenhouse gas buildup, use of wind to generate electricity has received increasing interest. Wind generation is commercially used in many parts of the world and the most common style of commercial wind turbine generator utilizes a rotor, typically with three blades. The rotor typically turns a horizontally oriented shaft, which provides input to a gear box, which increases the rotation speed and turns a generator which converts the shaft power into electrical power. Usually, the pitch of the blades can be adjusted to regulate the speed during normal operation and also to shut down the machine when wind speeds are excessive. Most modern wind turbines start operating when wind speeds reach about 12 miles per hour and achieve their rated power at about 25-30 miles per hour and shut down at wind speeds above 35-40 miles per hour.
Unfortunately, a great deal of potential power generation is lost because of the necessity of shutting down the windmill in wind speeds above 35-40 miles per hour. Wind turbines which do not use rotor blades have been patented but have not found commercial application. One such design is shown in U.S. Pat. No. 4,764,683. The generator uses a pair of helical rotors positioned so that a portion of the blades extend beyond forward and rear xe2x80x9cnacelles.xe2x80x9d
A vertical axis wind-powered generator is shown in U.S. Pat. No. 5,038,049. This device uses a cylindrical rotor having a vertical axis with a plurality of wind-driven veins. A curved inner modulator is mounted on the base inside the rotor to control the wind flow through the rotor. An inlet modulator is rotatably mounted on the base for controlling wind flow to the rotor.
It is an object of the present invention to provide a wind-driven turbine which is capable of generating electricity without having to shut down in winds in excess of 40 miles per hour.
The present invention is for a wind-driven turbine assembly useful for the generation of electricity. The assembly has a frame with a front opening for the entrance of the flow of wind and the frame has a floor, a right side, a left side, and a back. A right and a left turbine are rotatably supported by the top and floor of the frame. Each of the right and left turbines have a vertically oriented central support pipe having a plurality of air passageways therethrough. A plurality of blades are held by each of the vertically oriented support pipes and the blades are generally vertically oriented and extend outwardly to an outward edge so that as each turbine rotates its outer edge subscribes a circle within the frame. Each such circle has an outer edge oriented near the respective right side and left side of the frame. Each central support pipe has an upper and a lower end support frame for providing support means for holding the support pipe in a vertical position and at least one of the upper and lower end support frame has openings to permit the flow of air outwardly from an inner area of the support pipe. A nose cone is supported vertically in the front opening of the frame, having a rightwardly oriented face and a leftwardly oriented face for diverting the flow of wind away from the center of the front opening to create a right air stream and a left air stream. A right side door and a left side door is each hingedly held across the right and left sides respectively of the frame by a vertical hinge positioned nearer the front opening of the frame than the back opening of the frame. These side doors are movable from a closed position angularly aggressively to let more wind pass between the outer edges of the blades and the respective side doors. Each side door is biased toward the closed position whereby a right side airstream flows against the blades of the right turbine and along the right side door, and a left side airstream flows against the blades of the left turbine and along the left side door, thereby urging the turbines to turn in opposite directions. A back panel is held across the central area of the back of the frame and this back panel, together with the top, bottom, right turbine, and left turbine, form a rear central space. Means are provided for releasing air from the rear central space to the outside of the frame. A right and a left adjustable baffle are held across the back of the frame adjacent the back panel and the right and left adjustable baffles are hingedly held at the tight and left edges of the back panel. Means are provided for setting the amount of opening of the right and left adjustable baffles, whereby when a stream of air enters the front opening of the frame, such stream of air is directed by the nose cone into a right air stream and a left air stream. Part of the right and left air streams pass through the air passageways in the vertically oriented central support pipes of the right and left turbines and exit through the support pipe. Electrical generating means are operably connected to the turbines to produce electrical energy. A wide mesh screen is placed over the front opening to prevent the entry of large objects which would interfere with the rotation of the turbines. Baffles may be provided within the frame to direct the flow of air in an optimum manner. Front, right, and left wind baffles may be further provided to control the flow of air into the front opening. The outside diameter of the turbines is typically between 2 and 8 feet, with 8 to 30 blades in each turbine.